Caxton Associates founder Bruce Kovner has made one of the largest donations in the history of the Juilliard School to endow its early-music program.

Kovner, who serves as chairman of the board at—arguably—the country's most prestigious school of music—will announce the $20 million gift today. The money will be used to fund Juilliard's graduate historical performance program.

Kovner, who retired from Caxton last year, has been giving as much as $1 million a year to the program for the last three years, to finance its curriculum development. Six years ago, he gave the school a major collection of music manuscripts.